Monitoring of the Lower Owens River Project has given Inyo County, the Los Angeles Department of Water and Power and residents an insight into how habitats on the project are developing.
Both LADWP and Inyo County Water Department officials said LORP goals were met this past year, despite dry conditions, and, over all, coordinated team-work between the LADPW and Inyo County, as well as consultants, has led to a growing habitat along the river.
The 2012 LORP Annual Report, prepared by staff from both the county and LADWP, contains the results of the fifth year of monitoring efforts, including: information from hydrologic monitoring; seasonal habitat flow – including the flood extent that is dictated by the amount of precipitation the Eastern Sierra received this year; a rapid assessment survey; land management; and saltcedar and weed control monitoring.
“Overall, the LADWP is very proud of the progress going on at the LORP,” Manager of Aqueduct Systems Jim Yannotta said. “We’re obtaining many of our goals.”
County leaders said this past year turned out to be a dry one, but cooperative efforts led to effective management and provided opportunities to improve current systems that are in place on the river.
“We’re five years into the project, but it doesn’t seem like it’s been five years,” Inyo County Water Department Director Bob Harrington said. “We had a dry year last year, so we didn’t do a large seasonal habitat flow, but we’re working with DWP and a consultant on how to manage that in the future.”
The hydrologic monitoring section of the report describes flow conditions on the LORP. Despite the dry year, the draft report says the LADWP was able to meet all its goals for seasonal flows and flooding this past year.
“For the 2011-12 water year, which covers October 2011 to September 2012, LADWP was fully compliant with all Stipulation and Order flow and reporting requirements,” the LORP Report Executive Summary states. “Off-River Lakes and Ponds level goals were fully met and the flows to the Delta achieved the required 6-9 (cubic-feet per second) annual flow.”
Harrington explained that the seasonal habitat flow is dependant on the Sierra snow pack, which was sufficient enough this spring to allow for seasonal flows, but on a reduced level.
The report says that the 2012 seasonal habitat flow was timed to occur with seed release of “woody riparian vegetation; which is an objective of the flow release pertinent to the 1997 Memorandum of Understanding.” The time for the peak 88 cfs flow to move down the Lower Owens River was 13 days, four hours from the LORP Intake to the Pumpback Station.
The draft report said seasonal LORP flooding covered about 1,800 acres, but “given the low peak release, only marginal inundation was observed during the peak flow in the LORP monitoring plots.”
The land management monitoring portion of the draft report was created by gathering information from monitoring on leases, of rare plants, streamside and irrigated pasture condition.
The goal of land management monitoring is to ensure that LORP lands that are appropriate for various uses are being managed for those uses.
“In general, pasture utilization adhered to standards established for both riparian (up to 40 percent being used) and upland (up to 65 percent being used) areas,” the report states. “Use on the Blackrock Lease was lower than most other leases in the project area, remaining well below all grazing standards. All other leases adhered to utilization standards except the Islands and Twin Lakes leases.”
The report goes on to say that the Islands Lease, a riparian area, was overused in the River Field with 50 percent being used, and the Twin Lakes lease had over-use in the riparian Upper and lower Blackrock Fields, 61 percent and 54 percent, respectively.
“Irrigated pastures in the Islands, Lone Pine and Delta Leases all had rated above the minimum rating of 80 percent in 2010; therefore, they did not need to be rated in 2012,” the draft report states. “The Thibaut Lease rated 82 percent in 2011 and 81 percent in 2012, meeting the minimum score of 80 percent.”
The report goes on to say that the lessee and LADWP are in the process of improving the score. “All irrigated pastures in the LORP will be evaluated again in 2013,” the report states.
Yannotta said the LADWP works closely with Inyo County, consultants and local leaseholders “so we don’t create any adverse affects while meeting our goals on the LORP.”
The report also says that area weed management efforts in 2012 essentially mirrored 2011 levels and all known Lepidium latifolium, or Pepperweed, sites within the LORP area were treated or surveyed in 2012. The report said most sites were treated three times, with four sites treated only twice, “because early spring flooding precluded herbicide application.”
Harrington said this is the first year that the LADWP is handling weed management on its Owens Valley properties, with county staff handling LORP weed management. “It’s a little early to tell what changes there will be with DWP taking on their property.”
In all, the report says invasive plant populations totaled 0.28 net acres, down 30 percent from 2011 levels, even though three new sites were identified this year.
“Of the 38 known sites, 50 percent, or 19 sites, had no plants present in 2012,” the report states. “After five continuous years of no growth, sites may be considered eradicated.”
The LADWP will hold a public meeting from 8-10 a.m. Thursday, Jan. 3 in the LADWP Administrative Office on Mandich Street in Bishop to discuss and receive comments regarding the draft annual report from the public.
To view the full 2012 Draft LORP Report, visit www.ladwp.com/LORP .